Caisson and method of sinking



April 10, 1945. ca. A. LONG CAISSON AND METHOD OF SINKING Filed April17, 1944 W ll 0 Z 5 Sheets-Sheet 1 INVENTOR.

A ril 10, 1945. G A, ONG 2,373,319

CAISSON AND METHOD OF SINKING Filed April 17, 1944 s Sheet Sheet 2 6 v(zzvza filo/ya INVENTOR.

April 10, 1945. v G LONG. 2,373,319

CAISSON AND METHOD OF smxms Filed April 17, 1944 s Sheets-Sheet 3 %q v v@W 7 ZUF6ZZZO/YG 7 INVENTOR.

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Patented Apr. 10, 1945 UNITED STATES This invention relates to theSinking of caisson's, pile tubes and the like and it has particularreference to an improved apparatus .for and method of accomplishment,

The principal object of the invention is 'to re- 1 duce, by means of aminimum number of steps, the excessive labor and costs inconstructingfoundation piles. ('Jonstruction of this character has, in the past,been carried out in a number of required depth is reached. Obviouslythen, the

step of filling the caisson with concrete may be pursued withoutrequiring the removal of mud from the casing which'is the expensiveandtime consuming step necessary in some other caisson v sinkingmethods.

Another object of the. invention is to include in the method ofconstructing caissons, the steps consisting of sinking an elongatedcasing by an uninterrupted drilling operation, in impregnating theformation immediately surrounding the casing at bed rock with grout andsubsequently removing the concentric tube through which is pumped thedrilling mud and later, the grout, pre paratory to the introduction ofconcrete. I

Still another object of the invention is to provide a caisson sinkingapparatus consisting of a special derrick having provisions forhydraulically tilting the same for battering the pile cas ings; aspecial rotary and hoist equipment and an elongated casing or shell in asingle piece provided in its lower end with aback pressure valve ofspecial design to resist bottom hole pressure tending to move counter topump pressure through the concentric tube'in the casing.

With the foregoing objects as paramount, the invention has furtherreference to certain features of accomplishment illustrated in theaccompanying drawings and to the novel steps of the method to bepresently described.

Figure 1 is a side elevational view of aderrick constructed according tothe present invention Figure 2- is a front elevational view thereof.Figure 3 is a side elevational view of the casing and drill of theinvention. v j

Figure 4 is a vertical sectional view thereof,

line 5 -5 on Figure 4. l

Figure 6 is a transverse sectional view taken on linewfionlrigure' l. Fiure! is afragmentary view in" vertical section of the boring tool andvalve? Figure 5 is a transverse sectional view taken on Figure 8 is aschematic side elevational view.

of the derrick showing the'casing partly in the earth,and

Figure 9 is a similar view but showing the derrick from the front 'andtilted slightlytobatter the casing insinkin'g;

' Continuing with a more detaileddes'cription of thedrawings, referenceis primarily made to Figures 1. and 2. wherein nu meralIU denotes theforemost l egs of the derrick which converge at their tops but arenormally disposed-in a plane perpendicular td'tne' earth except whentilted .ior battering in a" manner to be presently described. Therearm'ost legs I l converge towards each other and to the front legs attheir tops and suitable struts and braces 12 are appropriately arrangedon'the legs inthe conventional manner toassume and distribute strains.and stresses to which the structure may be subjected.

' Intermediate the foremost legs ll). of the derrick there is providedrelatively parallel and perpendicu-lar guides I I 3;supp01'ted bysuitable braces from the legs Ill. "These guides serve as tracks for theoppositelydisposed', elongated shoes M which serve as amounting torsrotary table l5 and its associated elements. i

Supported also'by the vertically movable shoes i4 is a' platform It onwhich is mounted the as sociated elements 0f the rotary, including themotor H and controls Hi. This platform likewise provides astaticnfor'the operators of the rotary and attendant elements;

' it will be observed that the four corners of the derrick foundation I9are supported upon hydraulic rams 20. opera-ted'i-n cylinders 2!. Thesecylinders have'communication between each other and with acompressortank 22' (Figs. 1 and 2) through the'm'edium of'a's'ystem ofpipes 23, pressure to selected ones of the cylinders 2| being controlledby valves 24. Thus; it may be seen that by actuating the valves'2fl,oneside of the derrick may be raised, as suggested by the in-- clinedlines in Figures 1, 2 and 9'in order to batter the casing 25 of thecaisson as suggestedin Figure 9 particularly. v Referring now to Figures3 to '7, inclusive; the caisson casing 253s sho'wn'as consisting of onecontinuous tubular body, pro ba bly made up of welded sections,consideringthat it often exceeds 100 feet in length. In this, amongother things, the actual process of sinking the caisson tube differsfrom the conventional drilling process wherein the pipe is set up asdrilling proceeds.

ity in the end of the head which communicates with the passage throughthe sleeve 28. The a pilot bit 28 is of conventional fishtail design andtherefore has fluid passages 30 therein.

Extending axially through the casing 25 isa tube 3| whose lower end isprovided with oppobottom of the hole and up around the lower end of thecasing. Pump pressure may be maintained thereon until the grout attainsa mechanical set but this is usually unnecessary due to the presence ofthe valve 31 whose peculiar construction and function is such that itwill resist heavy bottom hole pressure.

After the grout has been introduced as described, the complement beingdetermined by pump gauge pressure, the. tube 3| is rotated slightly todisconnect it from the pins 34 and it is Withdrawn from the casing 25.The casing is then filled with concrete and whether or not reinforcingsteel is prearranged in the casing would depend upon the specificationrequirements of e the engineers in charge of the particular projectsitely disposed, inverted L-shaped slots 32.' This 1 tube is adapted tobe withdrawn from and replaced in the casing 25 as occasion requires andwhen it is set down into the sleeve 28 of the drilling head, provisionis made in the form of a beveled recess 33 in the sleeve for guiding thelower end of the tube into the socket provided by the sleeve. The slots32 of the tube receive oppositely disposed pins 34 in the walls of thesocket and in this manner interlocked relationship of the tube andsleeve is effected.

Interiorly of the sleeve 28 and intermediate the ends thereof is ashoulder 35on which rests the lower end of the tube 3|. Starting at thisshoulder and terminating at a point spaced from the lower end of thepassage through the sleeve 28 is an inverted coniform cavity 36 toaccommodate a conformably shaped valve body 31, preferably constructedfrom wood. Below the valve body 31 is a coil spring 40 whose lower endrests upon the pin of the pilot bit 29 and is effective to hold thevalve body 31 in closed position except when fluid pressure is imposedthereon in operation.

In operation, the derrick I0 is oriented with respect to point ofoperations and the casing 25, equipped with the drilling head 25 iselevated through the medium of the line drum assembly and draw works 4|,much in the customary manner of drilling. The tube 3| is run into thecasll'lg and interlocked with the sleeve 28, as explained. The rotary I5 is set into operation and drilling begins, the cuttings from the bit29 and drilling head 26 being elevated in the hole around the casing byfluid forced by pump pressure through the hose 42, swivel l3 and tube 3|and past the valvebody 31 which has been displaced by pressure, and intothe hole through the fluid passages 30 in the pilot bit 29.

It is important to note that as drilling progrosses, the inside of thecasing 25 remains dry and unlike other and conventional drilling methodsor processes, the mud does not at any time enter the casing. This makesfor speedier work and reduces materially the cost of sinking piles andcaissons because it obviates the final opera tion Of removing mud fromthe hole as by pumping, bailing and by other means. This is an expensiveand time consuming operation and is not entirely satisfactory even whenexpertly accomplished. When the desired depth is reached by the presentprocess, the operation is complete with the exception of introducinggrout, since the casing 25 is left in the hole as the form for theconcrete which is subsequently deposited therein.

When the casing 25 has been sunk to a predetermined depth the pipe 31 isflushed out with water and grout from a suitable reservoir such assuggested at 44 (Figs. 1 and 2) is pumped into the under construction,such as casing wall thick- .ness,- nature of the surrounding formationand the like.

'It is obvious from the foregoing that even though the casing, drilling:head and its attendant parts are left in the hole, the time saved bythe process described herein materially offsets the value of theseelements and beyond this, the caisson, having the benefit of thereinforcing supplied by the casing, possesses greater strength andendurance than piles similarly set up but wherein the casing. isremoved.

One outstanding characteristic which the present process possesses overother types of caisson sinking methods is the fact that the drillingoperation is continuous from beginning to end. Should there be anyinterruptions in the course of drilling, especially in quick sand, thesand would set up and further drilling would be rendered difiicult ifnot impossible to again start the caisson.

Manifestly, the construction and process as shown and described iscapable of some modification'and such modification as may be construedto fall within the scope and meaning of the appended claims is alsoconsidered to be within thespirit and intent of the invention.

What is claimed is:;

1. The hereindescribed method of sinking cais sons, characterized bycontinuously drilling into the earth a closed ended casing, incontinuously introducing drilling fluid through a restricted passagewayin said casing to the drilling end of said casing, in flushing saidpassageway at bedrock, in introducing,grout-through said passageway intothe formation immediately surrounding said casing, in removing saidpassageway from said casing and finally in filling said casing withconcrete.

2. The hereindescribed method of sinking caissons which consists incontinuously rotating an elongated, hollow tubular body to efiectpenetration of the earth thereby to a predetermined depth, incontinuously supplying the drilling end of said body with fluid, inmaintaining the drilling end of said body closed except for the downwardpassage of fluid, in ceasing theintroduction of fluid at bedrock andsubstituting grout therefor and finally in filling said body withconcrete.

3. The hereindescribed method of sinking caissons, piles and the like,the steps consisting in penetrating the earth. to a predetermined depthby uninterrupted rotating a hollow, tubular body, in continuouslywetting the formation in advance of saidbody to remove loosened earth,in suspending the wetting operation at bedrock, in introducing groutinto the formation through said body and finally in filling, said bodywith concrete.

4. A method of constructing caissons, the steps consisting inuninterruptedly boring into the earth with an elongated and hollowtubular body through the body at a predetermined depth and insubstituting the fluid with grout andfinally in filling the hollow bodywith concrete.

5. The method of constructing caissons, the steps consisting in sinkinga hollow, tubular body through unconsolidated formation to bedrock byuninterruptedly rotating the body and in washing cuttings from aroundsaid body as the latter penetrates the earth, in impregnating, thesurrounding formation with grout and finally in filling the hollow bodywith concrete.

6. Apparatus for constructing caissons including an elongated, hollowcasing having a truncated drilling head closing one end thereof, anintegral and concentrically related sleeve in said 4 drilling head whosepassageway is straight walled at its upper end and threaded at its lowerend and provided intermediate said ends with an inverted coniformchamber, a correspondingly shaped non-metallic valve body disposed insaid chamber, a pilot bit disposed in the threaded end of saidpassageway, a coiled spring interposed between the shank of said bit andsaid valve body to urge the latter to closed position in said chamber, afluid transporting tube extending axially through said casing andentering the upper end of said passageway and means carried jointly bysaid tube and passageway for releasably holding said tube.

7. Apparatus for sinking caissons and piles comprising an elongated andtubular hollow casing having a trunco-coniform drilling head on" oneend, a pilot bit carried by said drilling head, means removablyconnected to said drilling head interiorly of said casing forintroducing drilling fluid and grout into the formation through saidcasing and said pilot bit, a sleeve rising axially in said drilling headwhose passage is beveled at its top to receive the lower end of saidremovable means and is further provided with a valve chamberintermediate its ends; valve means in said chamber for closing saidpassage against bottom hole pressure and spring means between said bitand valve means for urging the latter to closed position in saidchamber..

GEORGE A. LONG.

